Conventionally, related word presentation apparatuses have been proposed. Such related word presentation apparatuses are intended to present, as a search condition, a related word having a high degree of relevance with an aim to prevent omission in search, for example, in the case where the number of search results is small or other cases at the time of displaying search results obtained based on a previous search condition inputted by the user (for example, see Patent Reference 1). With this related word presentation apparatus, the user selects one of the presented related words in order to obtain new search results in addition to the search results obtained based on the first search condition. The related word presentation apparatus logically connects the selected related word and the search condition (connects the both by taking a logical sum of the related word and the search condition), and performs a search according to the logically connected search condition. Here, the related word presented by the user is a related word closely related to the search condition inputted by the user, and thus the user can gradually increase the number of search results based on the firstly obtained search results.
In addition, text mining programs have been proposed. Such text mining programs are intended to present information indicating an intervening word which is associated with two words inputted by a user (for example, see Patent Reference 2).    Patent Reference 1: Japanese Unexamined Patent Application Publication No. 10-334106    Patent Reference 2: Japanese Unexamined Patent Application Publication No. 2004-21763Disclosure of InventionProblems that Invention is to Solve
However, a conventional related word presentation apparatus merely presents a related word according to a search condition, and cannot present a user the reason why the related word is presented according to the search condition. In this case, if the user cannot understand the relationship between the related word and the search condition, a user's selection of a related word causes a problem that currently obtained search results are totally different from the search results obtained according to a search condition. In a similar case, the user thinks that the related word presented by the related word presentation apparatus is obtained by mistake, and thus a problem arises that the user has difficulty in selecting a related word whose relationship with the search condition cannot be understood. FIG. 14 is a diagram showing an example of a conventional display of search results and related words. FIG. 14 shows an exemplary presentation in the case where the user firstly inputs a search condition of “Information” for the purpose of searching out a program related to health information. The presentation includes (i) the search results, and (ii) “Taro Matsushita” who appears in a talk and information program and “Jiro Matsushita” who appears in a health and information program as related words according to the search condition “Information”. At this time, in the case where the user attempts to perform further search by selecting one of the presented related words, the user should select the related word “Jiro Matsushita” for the purpose of searching out a health information program. However, since there is no presentation of “Health and Information” indicating the relationship between the search condition “Information” and the related word “Jiro Matsushita”, the user has difficulty in making a right selection from among the related words “Taro Matsushita” and “Jiro Matsushita”.
In addition, the conventional text mining program merely presents a route word which is associated with two words inputted by the user, and thus the route word is selected without reflecting the search condition inputted by the user, the obtained search results, and the user's preference. For this reason, there are a case where the user does not know the presented route word and a case where the word presented to the user is a word having a little relationship with the inputted search condition and the obtained search result. The problem is that the user cannot understand the relationship between the two words.
The search condition is not limited to a search condition inputted by the user, and the search condition may be automatically extracted from program information and the like. The same problem arises even in the latter case.
The present invention has been made in view of the aforementioned circumstances, and aims to provide an interactive program search apparatus and an interactive program search method which allow the user to easily understand the relationship between the obtained search conditions and the presented related words.
Means to Solve the Problems
In order to achieve the above-described objects, an interactive program search apparatus which searches out a program using a search word includes: a program information storage unit configured to store program information indicating contents of programs on a per program basis; an association dictionary storage unit configured to store an association dictionary in which words included in the program information are stored in association with each other; an obtaining unit configured to obtain the search word; an obtainment history storage unit configured to store, as obtainment history information, the search word obtained by the obtaining unit and an obtainment frequency of the search word; a program search unit configured to search out programs from the program information using, as a search condition, the search word included in the obtainment history information; an association-source word extracting unit configured to extract an association-source word which is associated with an associated word, from among the words included in the obtainment history information; an associated word extracting unit configured to extract the associated word associated with the association-source word using the association dictionary; a reason word extracting unit configured to extract, as a reason word indicating a relationship between the association-source word and the associated word, a word included in the obtainment history information from among words each having (i) a degree of relevance equal to or greater than a predetermined degree of relevance with the association-source word and (ii) a degree of relevance equal to or greater than a predetermined degree of relevance with the associated word; and a display unit configured to display program search results which are the programs searched out by the program search unit, the associated word, and the reason word.
This configuration allows obtainment history information related to (i) the search word inputted by the user or obtained from program information and (ii) the program information of the program selectively determined by the user to be reflected on a reason word indicating the relationship between the search condition and the associated word associated with the search condition. The obtainment history information is composed of words known by the user, and thus the user can understand the meaning of the reason word and easily understand the relationship between the inputted search condition and the displayed related word.
It is to be noted that the present invention can be implemented as an interactive program search apparatus including such unique processing units, but also as an interactive program search method including steps corresponding to the unique units included in the interactive program search apparatus and as a program causing a computer to execute the unique steps included in the interactive program search method. As a matter of course, such program can be distributed by means of recording media such as CD-ROMs (Compact Disc-Read Only Memory) and communication networks such as the Internet.
Effects of the Invention
As described above, the interactive program search apparatus according to the present invention (I) allows obtainment history information related to (i) the search word inputted by the user or obtained from program information and (ii) the program information of the program selectively determined by the user to be reflected on a reason word indicating the relationship between the search condition and the associated word associated with the search condition, and (II) allows presentation of the reason word to the user. Therefore, the user looking at a known or understandable reason word can easily understand the relationship between the search condition and the related word.